Interface IEntityRetriever
This is the core context class used for querying all data in the LemonEdge platform, regardless if the context is executing directly connected to the database, or across a web service
This context is always provided within UI and Context APIs, ensuring you can always access data wherever it is needed from a view, command, server running task or elsewhere
All queries can refer to the interface for a type, or the class that implements it
Inherited Members
Namespace: LemonEdge.Core
Assembly: API.dll
Syntax
public interface IEntityRetriever : IDisposable
Properties
CanvasID
The Canvas this context is running in. Do not change the canvas, it is handled by the system given the canvas the User is currently running in, and will be ignored by the web service anyway
Declaration
Guid? CanvasID { get; set; }
Property Value
Type | Description |
---|---|
System.Nullable<System.Guid> |
GetUseAsOfDate
The as of date all queries in the context are running in. You should not change this for a system provided IENtityRetriever, however you can get a new IEntityRetriever and run that with any As Of Date you wish
Declaration
DateTimeOffset? GetUseAsOfDate { get; }
Property Value
Type | Description |
---|---|
System.Nullable<System.DateTimeOffset> |
GetUseLabels
If this context is running within a server, or for non UI displayed reasons, you don't need queries returning labels. This significantly imprives the speed of queries that have a lot of relationships.
This indicates if queries will populate _Label fields for relationships by default or not
Declaration
bool GetUseLabels { get; }
Property Value
Type | Description |
---|---|
System.Boolean |
IsDirectDBConnection
Indicates if this context is directly connected to the database server or not
Used by certain validation that you only want to run when connected to the db as could be expensive.
If not connected it wont be run, but will be run by the service when it processes the changes and performs its own validationDeclaration
bool IsDirectDBConnection { get; }
Property Value
Type | Description |
---|---|
System.Boolean |
IsODataQuery
Indicates if this underlying query is being executed through a web service or direct db connection
If this is a direct db connection some queries are changed to make sure the results are consistent across service or direct db connection.
For instance string comparisons are case insensitive against the database so we change comparisons to use ToLower to make sure in memory queries provide the same results. We can't do this on an OData query as ToLower isn't translatable from Linq to OData, and the odata web service implementation is performing a case insensitive comparison anyway
Declaration
bool IsODataQuery { get; }
Property Value
Type | Description |
---|---|
System.Boolean |
Methods
ExecuteCustomQuery<T>(String, Object[])
Executes the specified CustomServiceQueryExtender<T> which enables LINQ style queries to join across all entities in the system in one query
Declaration
Task<IEnumerable<T>> ExecuteCustomQuery<T>(string customQueryName, params object[] parameters)
where T : IBaseEntity
Parameters
Type | Name | Description |
---|---|---|
System.String | customQueryName | The name of the method in the class that inherits the CustomServiceQueryExtender that you want to execute |
System.Object[] | parameters | A param array of parameters to be passed to this method |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<T>> | A task holding the results of executing the custom LINQ query |
Type Parameters
Name | Description |
---|---|
T | The type of item returned by the CustomServiceQueryExtender |
Remarks
The QueryableExecuter works for retrieveing and querying results easily through this interface that abstracts if its running through the web service or directly to the database. However it only allows queries against one type of entity.
Using a CustomServiceQueryExtender<T> enables you to create a normal IQueryable query that joins across multiple entity types, and is dynamically translated into sql for you. Again this works across the web service or directly connected to the database.
See CustomServiceQueryExtender<T> for more information, but the intention is that these are used only for queries across multiple entity types for performance. All other queries can be resolved using QueryableExecuter which are faster and more efficient for querying individual entity types that do not require joins.
See Also
ExecuteQuery(QueryableExecuter)
Takes a QueryableExecuter and executes the query against the database (possibly via a web service) and returns the results
If this context contains any changes of the query entity type then those changes won't be overwritten by the results, they will be included if they match the QueryableExecuter filter
Declaration
Task<IEnumerable<IBaseEntity>> ExecuteQuery(QueryableExecuter items)
Parameters
Type | Name | Description |
---|---|---|
QueryableExecuter | items | The queryable executer containing the definition of the query to execute. Can be created from GetItems(Type) |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<IBaseEntity>> | A task holding the result set of the query as an enumeration |
ExecuteQuery<T>(QueryableExecuter<T>)
Takes a QueryableExecuter<T> and executes the query against the database (possibly via a web service) and returns the results
If this context contains any changes of type T
then those changes won't be overwritten by the results, they will be included if they match the QueryableExecuter filter
Declaration
Task<IEnumerable<T>> ExecuteQuery<T>(QueryableExecuter<T> items)
where T : IBaseEntity
Parameters
Type | Name | Description |
---|---|---|
QueryableExecuter<T> | items | The queryable executer containing the definition of the query to execute. Can be created from GetItems<T>() |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<T>> | A task holding the result set of the query as an enumeration |
Type Parameters
Name | Description |
---|---|
T | The type of items we are executing a query against |
ExecuteQueryAsCSV(Nullable<DateTimeOffset>, Nullable<Guid>, String, String, String)
Executes the specified query and returns the results as a CSV file in bytes
Declaration
Task<byte[]> ExecuteQueryAsCSV(DateTimeOffset? asOfDate, Guid? canvasID, string typeKey, string base64SerializedQueryExecuter, string base64SerializedColumnsToReturn)
Parameters
Type | Name | Description |
---|---|---|
System.Nullable<System.DateTimeOffset> | asOfDate | Runs the query using the specified As Of Date. Null indicates no as of date, and to just use the current data. |
System.Nullable<System.Guid> | canvasID | Runs the query using the specified Canvas. Null indicates no canvas, and to just use the current main system. |
System.String | typeKey | The key (UniqueKey) of the entity type we want to run a query against. |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter containing the query to execute against this type |
System.String | base64SerializedColumnsToReturn | A serialized string of an array of ColumnDescriptor indicating the properties for the type to return. Null indicates all properties for this entity type. |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Byte[]> | A Task holding the result of running the specified query, converting the results to a formatted csv file and then to a byte array |
ExecuteSQLResultsAsCSV(Guid, String, String, String)
Executes the specified ISQLWrapper and returns the results as a byte array of a csv fotmatted file of the results
Declaration
Task<byte[]> ExecuteSQLResultsAsCSV(Guid sqlWrapperID, string base64SerializedParameters, string base64SerializedQueryExecuter, string base64SerializedColumnsToReturn)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | sqlWrapperID | The ID of the SQL Wrapper to execute |
System.String | base64SerializedParameters | A serialized System.Collections.Generic.Dictionary<TKey, TValue> of String, String, holding the parameters for this query. The key the ParameterName for the paramater, and the value the value |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter<T> (of type ISQLWrapperResult or the custom Complex or Entity type that can also hold the results) containing the query to execute against this result set |
System.String | base64SerializedColumnsToReturn | A serialized string of an array of ColumnDescriptor indicating the columns for the SQLWrapper query to return. Null indicates all columns defined in this SQLWrapper. |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Byte[]> | A Task holding the result of running the specified query, converting the results to a formatted csv file and then to a byte array |
GetItemByID(Type, Guid)
Returns the item of type type
specified by the id
Declaration
Task<IBaseEntity> GetItemByID(Type type, Guid id)
Parameters
Type | Name | Description |
---|---|---|
System.Type | type | The type of entity to return |
System.Guid | id | The ID of the entity to return |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<IBaseEntity> | A task holding the result of the request |
GetItemByID<T>(Guid)
Returns the item of type T
specified by the id
Declaration
Task<T> GetItemByID<T>(Guid id)
where T : IBaseEntity
Parameters
Type | Name | Description |
---|---|---|
System.Guid | id | The ID of the entity to return |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<T> | A task holding the result of the request |
Type Parameters
Name | Description |
---|---|
T | The type of entity to return |
GetItems(Type)
Returns a new QueryableExecuter for the specified type of item. This can be used to create a query for retrieveing certain items of type type
, which can be executed using ExecuteQuery(QueryableExecuter)
Declaration
QueryableExecuter GetItems(Type type)
Parameters
Type | Name | Description |
---|---|---|
System.Type | type | The type of items that the QueryableExecuter can query |
Returns
Type | Description |
---|---|
QueryableExecuter | The new QueryableExecuter for this specified type |
GetItems<T>()
Returns a new QueryableExecuter<T> for the specified type of item. This can be used to create a query for retrieveing certain items of type T
, which can be executed using ExecuteQuery<T>(QueryableExecuter<T>)
Declaration
QueryableExecuter<T> GetItems<T>()
where T : IBaseEntity
Returns
Type | Description |
---|---|
QueryableExecuter<T> | The new QueryableExecuter for this specified type |
Type Parameters
Name | Description |
---|---|
T | The type of items that the QueryableExecuter can query |
GetQueryCount(Nullable<DateTimeOffset>, Nullable<Guid>, String, String, String)
Executes the specified query and returns the count of the matching results
Declaration
Task<int> GetQueryCount(DateTimeOffset? asOfDate, Guid? canvasID, string typeKey, string base64SerializedQueryExecuter, string base64SerializedColumnsToReturn)
Parameters
Type | Name | Description |
---|---|---|
System.Nullable<System.DateTimeOffset> | asOfDate | Runs the query using the specified As Of Date. Null indicates no as of date, and to just use the current data. |
System.Nullable<System.Guid> | canvasID | Runs the query using the specified Canvas. Null indicates no canvas, and to just use the current main system. |
System.String | typeKey | The key (UniqueKey) of the entity type we want to run a query against. |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter containing the query to execute against this type |
System.String | base64SerializedColumnsToReturn | A serialized string of an array of ColumnDescriptor indicating the properties for the type to return. Null indicates all properties for this entity type. |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Int32> | A task holding the count of the row results from running the specified query |
GetSQLResults(Guid, String, String)
Executes the specified ISQLWrapper and returns the results set of ISQLWrapperResults. SQLWrapperInterpretor can be used to interrogate the values of each result item.
Declaration
Task<IEnumerable<ISQLWrapperResult>> GetSQLResults(Guid sqlWrapperID, string base64SerializedParameters, string base64SerializedQueryExecuter)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | sqlWrapperID | The ID of the SQL Wrapper to execute |
System.String | base64SerializedParameters | A serialized System.Collections.Generic.Dictionary<TKey, TValue> of String, String, holding the parameters for this query. The key the ParameterName for the paramater, and the value the value |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter<T> of type ISQLWrapperResult containing the query to execute against this result set |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<ISQLWrapperResult>> | A task holding the results of your query. SQLWrapperInterpretor can be used to interrogate the values of each result item. |
Remarks
This function is extremely powerful as it allows you to execute any custm created SQLWrapper to get high performant results from a context anywhere within your application code
See Also
GetSQLResults<T>(Guid, String, String)
Executes the specified sqlWrapperID
and returns the results set as a collection of specified custom types (either or complex or entity types) that have properties matching the Name of the columns returned by the SQLWrapper
Declaration
Task<IEnumerable<T>> GetSQLResults<T>(Guid sqlWrapperID, string base64SerializedParameters, string base64SerializedQueryExecuter)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | sqlWrapperID | The ID of the SQL Wrapper to execute |
System.String | base64SerializedParameters | A serialized System.Collections.Generic.Dictionary<TKey, TValue> of String, String, holding the parameters for this query. The key the ParameterName for the paramater, and the value the value |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter<T> of type |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<T>> | A task holding the results of the query |
Type Parameters
Name | Description |
---|---|
T | The type (eith a complex or entity type) that has properties matching the columns returned by the query |
GetSQLResultsCount(Guid, String, String)
Executes the specified sqlWrapperID
and returns the count of the results
Declaration
Task<int> GetSQLResultsCount(Guid sqlWrapperID, string base64SerializedParameters, string base64SerializedQueryExecuter)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | sqlWrapperID | The ID of the SQL Wrapper to execute |
System.String | base64SerializedParameters | A serialized System.Collections.Generic.Dictionary<TKey, TValue> of String, String, holding the parameters for this query. The key the ParameterName for the paramater, and the value the value |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter<T> of type ISQLWrapperResult containing the query to execute against this result set |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Int32> | A task holding the count of the number of items that would be returned from executing this query |
GetSQLResultsCount<T>(Guid, String, String)
Executes the specified sqlWrapperID
and returns the count of the specified custom types (either or complex or entity types) that have properties matching the Name of the columns returned by the SQLWrapper
Declaration
Task<int> GetSQLResultsCount<T>(Guid sqlWrapperID, string base64SerializedParameters, string base64SerializedQueryExecuter)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | sqlWrapperID | The ID of the SQL Wrapper to execute |
System.String | base64SerializedParameters | A serialized System.Collections.Generic.Dictionary<TKey, TValue> of String, String, holding the parameters for this query. The key the ParameterName for the paramater, and the value the value |
System.String | base64SerializedQueryExecuter | The serialization string of a QueryableExecuter<T> of type |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task<System.Int32> | A task holding the count of the number of results that would be returned from executing this query |
Type Parameters
Name | Description |
---|---|
T | The type (eith a complex or entity type) that has properties matching the columns returned by the query |
UseAsOfDate(DateTimeOffset)
Specifies the as of date all queries in the context are running in. You should not change this for a system provided IENtityRetriever, however you can get a new IEntityRetriever and run that with any As Of Date you wish
If you are returning items as of a prior point in time you should not attempt to modify them - it will fail
Declaration
IEntityRetriever UseAsOfDate(DateTimeOffset asOfDate)
Parameters
Type | Name | Description |
---|---|---|
System.DateTimeOffset | asOfDate | The as of date to use for running queries from this context with. |
Returns
Type | Description |
---|---|
IEntityRetriever | The current context so commands can be chained |
UseCanvas(Guid)
Specifies the context should run in the specified Canvas. Do not change the canvas, it is handled by the system given the canvas the User is currently running in, and will be ignored by the web service anyway
Declaration
IEntityRetriever UseCanvas(Guid canvasID)
Parameters
Type | Name | Description |
---|---|---|
System.Guid | canvasID | Th ID of the canvas this context should run in |
Returns
Type | Description |
---|---|
IEntityRetriever | The current context so commands can be chained |
UseLabels(Boolean)
Indicates if items returned will have relationship fields with _Label properties automatically populated or not.
This is only required for items that are displayed in the UI, all other items don't need this and can benefit from performance improvements
Declaration
IEntityRetriever UseLabels(bool useLabels)
Parameters
Type | Name | Description |
---|---|---|
System.Boolean | useLabels | Indicates if queries should use labels or not |
Returns
Type | Description |
---|---|
IEntityRetriever | The current context so commands can be chained |